Exemplo n.º 1
0
 /**
  * setup a dummy mortgage payment that gives us a large set of values so that the table can resize
  * its columns based on what is likely a "worst-case" scenario. this should leave plenty of room
  * for real mortgage payments without making the window overly large and yet still reacting to
  * local system visual sizes.
  */
 private void sizeMortgageTable() {
   resetMortgage();
   final MortgagePayment p = new MortgagePayment(999999.99, 999999.99, 999999.99, 99999999.99);
   paymentsModel.setPayments(new MortgagePayment[] {p});
   paymentsTable.resizeTableColumns();
   paymentsTable.limitTableViewport(VISIBLE_PAYMENT_TABLE_ROWS, true, false);
   resetMortgage();
 }
Exemplo n.º 2
0
  /**
   * Utility method that will calculate a new mortgage payment and payment breakdown based on the
   * user's current selection.
   */
  private void calculateMortgage() {
    boolean inputValid = true;

    // fetch the new values from the data entry fields and calculate a
    // new mortgage
    double principal = 0.0;
    try {
      final String principalText = fieldPrincipal.getText();
      principal = FMT_PRINCIPAL.parse(principalText).doubleValue();
      if (principal <= 0.0) {
        invalidInput(fieldPrincipal, MSG_PRINCIPAL_NEGATIVE);
        inputValid = false;
      }
    } catch (ParseException ex) {
      invalidInput(fieldPrincipal, MSG_INVALID_INPUT);
      inputValid = false;
    }

    double rate = 0.0;
    if (inputValid) {
      try {
        final String rateText = fieldRate.getText();
        rate = FMT_RATE.parse(rateText).doubleValue();
        if (rate <= 0.0) {
          invalidInput(fieldRate, MSG_RATE_NEGATIVE);
          inputValid = false;
        }
      } catch (ParseException ex) {
        invalidInput(fieldRate, MSG_INVALID_INPUT);
        inputValid = false;
      }
    }

    int term = 0;
    if (inputValid) {
      try {
        final String termText = fieldTerm.getText();
        term = FMT_TERM.parse(termText).intValue();
        if (term <= 0) {
          invalidInput(fieldTerm, MSG_TERM_NEGATIVE);
          inputValid = false;
        }
      } catch (ParseException ex) {
        invalidInput(fieldTerm, MSG_INVALID_INPUT);
        inputValid = false;
      }
    }

    if (inputValid) {
      // create a new Mortgage object from the selected mortgage terms and
      // then update the principal with the user's requested value
      final Mortgage mortgage = new Mortgage(principal, rate, term);

      // format the mortgage payment into a user-friendly message
      final Object[] values = {new Double(mortgage.getPayment())};
      final String message = MessageFormat.format(MSG_PAYMENT, values);

      // update our message label and payment data and force our UI
      // to repaint itself with the new mortgage results
      labelMessage.setText(message);
      paymentsModel.setPayments(mortgage.getPayments());

      // create a data set so the chart may be updated with the mortgage
      // payment detail
      final MortgagePayment[] payments = mortgage.getPayments();
      final double[][] chartData = new double[2][payments.length];
      for (int i = 0; i < payments.length; i++) {
        chartData[0][i] = payments[i].getInterest().doubleValue();
        chartData[1][i] = payments[i].getPrincipal().doubleValue();
      }

      final String[] chartDataNames = {"Interest", "Principal"};
      final NumberFormat[] formats = {new DecimalFormat("#,##0"), new DecimalFormat("$ #,##0.00")};

      paymentsChart.setData(chartData, chartDataNames, formats);

      repaint();
    }
  }
Exemplo n.º 3
0
 /**
  * Utility method that will reset the mortgage to an empty value and inform the user they need to
  * recalculate.
  */
 private void resetMortgage() {
   labelMessage.setText(MSG_CALCULATE);
   paymentsChart.clearData();
   paymentsModel.setPayments(new MortgagePayment[0]);
   repaint();
 }